I have a (mostly) standard phpBB forum so right now, images that are posted in [IMG] BB-tags don't have an alt text. I would like to change this and I'm doubting between two options:
- Use the topic title as alt text
- Use the most used words in the first post as alt text (I have a mod installed that sets those words as meta keywords)
A page has a maximum of 30 posts and the subforums that have a lot of pictures aren't accessible to Google. So at most, I think there will be 5 images per page. Is using the same alt text 5 times bad SEO-wise? Is there anything else I can do to get the right keywords to add?